Tapeless leadframe package with underside resin and solder contact

ABSTRACT

The present disclosure is directed to a semiconductor die on a tapeless leadframe and covered in encapsulant. The semiconductor package includes leads formed from the leadframe and electrically coupled to the semiconductor die, the leads being accessible through electrical contacts embedded in the encapsulant. Openings between the leads and the leadframe are formed from etching recesses from opposing sides of the leadframe. The resulting openings have non-uniform sidewalls. The leadframe is further electrically or thermally coupled to electrical contacts embedded in the encapsulant. The embedded electrical contacts forming a land grid array.

BACKGROUND Technical Field

The present disclosure is directed to an encapsulated semiconductor dieand leadframe package that resists flexing.

Description of the Related Art

Semiconductor packages often include a semiconductor die and a leadframethat provides an interface between contacts and the semiconductor die.The semiconductor package can include an encapsulant to secure theelements of the package into a single discrete unit. The semiconductordie is typically placed on the leadframe, and the combination is coveredwith encapsulant in an application chamber. The encapsulant is typicallyapplied at high pressure or temperature, and is then allowed to cool andsolidify around the package elements.

Unfortunately, as die and leadframe sizes continue to shrink, thepackages become more susceptible to warping, crumpling, and fracturing.The fragility of the packages greatly increases the difficulty ofhandling the packages during the manufacturing process and greatlydecreases overall percentage of viable packages from each manufacturingbatch.

BRIEF SUMMARY

The present disclosure is directed to a semiconductor package includinga thin leadframe with recesses etched into opposing sides of theleadframe. A first subset of recesses on a first side of the leadframehouse electrical contacts, and a second subset of recesses on the firstside combine with a third subset of recesses on a second side of theleadframe to form openings in the leadframe. The openings separate theleadframe from leads formed out of the leadframe. The distance betweenthe sidewalls of the openings varies from the first side of theleadframe to the second side as an artifact from the opening formationby etching recesses. A semiconductor die is attached to the second sideof the leadframe and connectors are used to electrically connect the dieto the leads formed from the leadframe. The package elements areencapsulated, with the encapsulant then partially removed to expose theelectrical contacts through the encapsulant.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a leadframe with recesses etched ina first side.

FIG. 2 is a cross-sectional view of electrical contacts in the recessesof the leadframe of FIG. 1 where the electrical contacts are covered byan encapsulant.

FIG. 3 is a cross-sectional view of the leadframe of FIG. 2 flipped overwith recesses etched in a second side of the leadframe.

FIG. 4 is a cross-sectional view of a die attached to the leadframe ofFIG. 3.

FIG. 5 is a top plan view of the leadframe and die of FIG. 4, with FIG.4 taken at cross-section line AA of FIG. 5.

FIG. 6 is a cross-sectional view of the die and leadframe of FIG. 4 withan encapsulant on the second side of the leadframe.

FIG. 7 is a cross-sectional view of the encapsulated leadframe packageof FIG. 6 after removal of some of the encapsulant on the first side ofthe leadframe to expose the electrical contacts.

FIG. 8 is a cross-sectional view of an alternate embodiment of aleadframe package in which leads do not extend to an edge of anencapsulant.

FIG. 9 is a cross-sectional view of an alternate embodiment of aleadframe package in which two semiconductor die are attached to aleadframe in a stack.

DETAILED DESCRIPTION

In the following description, certain specific details are set forth inorder to provide a thorough understanding of various embodiments of thedisclosure. However, one skilled in the art will understand that thedisclosure may be practiced without these specific details. In otherinstances, well-known structures associated with electronic componentsand fabrication techniques have not been described in detail to avoidunnecessarily obscuring the descriptions of the embodiments of thepresent disclosure.

Unless the context requires otherwise, throughout the specification andclaims that follow, the word “comprise” and variations thereof, such as“comprises” and “comprising,” are to be construed in an open, inclusivesense, that is, as “including, but not limited to.”

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure or characteristicdescribed in connection with the embodiment is included in at least oneembodiment. Thus, the appearances of the phrases “in one embodiment” or“in an embodiment” in various places throughout this specification arenot necessarily all referring to the same embodiment. Furthermore, theparticular features, structures, or characteristics may be combined inany suitable manner in one or more embodiments.

As used in this specification and the appended claims, the singularforms “a,” “an,” and “the” include plural referents unless the contentclearly dictates otherwise. It should also be noted that the term “or”is generally employed in its sense including “and/or” unless the contentclearly dictates otherwise.

As used in the specification and appended claims, the use of“correspond,” “corresponds,” and “corresponding” is intended to describea ratio of or a similarity between referenced objects. The use of“correspond” or one of its forms should not be construed to mean theexact shape or size.

Throughout the specification, the term “layer” is used in its broadestsense to include a thin film, a cap, or the like, and one layer may becomposed of multiple sub-layers.

Specific embodiments of leadframe packages are described herein;however, the present disclosure and the reference to certain materials,dimensions, and the details and ordering of processing steps areexemplary and should not be limited to those shown.

The present disclosure is generally directed to leadframe die packages,such as packages in FIGS. 7-9 that include encapsulant on both sides ofthe leadframe. The packages include one or more die that are attached toan etched leadframe that is etched on two opposing sides to formrecesses and openings. The recesses are filled with electrical contactsand the openings separate the leadframe from leads in the leadframe diepackage. The electrical contacts are formed in the recesses and have asurface that is coplanar with a surface of the encapsulant. The recessescan exhibit a shape that resembles a portion of a sphere, with theelectrical contacts exhibiting a shape that resembles a differentportion of a sphere with a similar radius. The package includesencapsulant, with openings in the encapsulant for the electricalcontacts or other elements of the package. The package includesencapsulant on two sides of the leadframe to help prevent warpage,crumpling, and fracturing.

FIGS. 1-7 are views of a package 100 in various stages of a process offorming the package. FIG. 7 represents one embodiment of a finishedleadframe die package 100. The leadframe package 100 includes aleadframe 102 supporting a semiconductor die 402. The semiconductor die402 is electrically coupled to leads 304 formed from the leadframe 102.The leads 304 are separated from a central portion of the leadframeusing an etching process performed from both sides of the leadframe 102.This etching process forms openings between the leads 304 and theleadframe 102 forms a non-uniform sidewall surface 303. Thesemiconductor die 402 and the leadframe 102 are surrounded byencapsulant to protect the leadframe package 100 and give the leadframepackage 100 additional structural support, with the particularapplication of encapsulant protecting the leadframe from warpage,crumpling, and fracturing.

The package 100 includes a plurality of electrical contacts 202, whichhave a surface 305 that is coplanar with a surface 307 of a firstportion 204 of the encapsulant 602. The electrical contacts may besolder balls that once reflowed fill in recesses 110, see FIG. 1.

FIGS. 1-4, 6 and 7 are views of various steps of a process to fabricatethe leadframe package 100 depicted in FIG. 7. FIG. 5 is a top down viewof the die and leadframe package to show relationships of the variouscomponents of the package. FIG. 1 is a cross-sectional view of theleadframe package 100 after being etched on a first side 111 to formrecesses 108 and 110. FIG. 2 is a cross-sectional view of the leadframe102 including electrical contacts 202 formed in a first group 110 of therecesses. The first portion of encapsulant 204 is formed on theelectrical contacts 202 and in the second group 108 of recesses. Then inFIG. 3 the leadframe 102 is etched on a second side 113. FIG. 4 is across-sectional view of the leadframe that corresponds to thecross-sectional line A-A in FIG. 5. FIG. 4 includes a semiconductor die402 coupled to the leadframe 102 and the leads 304. FIG. 6 is across-sectional view of a second portion 602 of encapsulant covering thedie and the second side of the leadframe 102. Then, in FIG. 7, the firstencapsulant 204 is partially removed to expose the surface 305 of theelectrical contacts 202. These steps and the various embodiments of thedevice are described in greater detail below.

As represented in the cross-sectional view of FIG. 1, assembly of theleadframe package 100 begins with the leadframe 102. The leadframe 102provides structure and support for the die. The leadframe may carry oneor more signals from the semiconductor die to an exterior portion, suchas a lead 304 of the leadframe package 100. In some embodiments, theleadframe 102 structurally supports the semiconductor die during thepackaging process. The leadframe 102 may be made of any suitablematerial for providing structure or signal communication, such asvarious metals like copper or a metal-alloy. In some embodiments, theleadframe 102 may be a tapeless leadframe that has no tape used on thebottom surface of the leadframe to secure the whole leadframe partstogether in place during manufacturing.

In some embodiments, the leadframe 102 has a thickness less than orequal to 100 μm. At a thickness less than or equal to 100 μm, theleadframe becomes fragile and prone to warpage, crumpling, or fracturingduring manufacturing and use. One of the issues observed is frowningwarpage in which a different rate of cooling of various elements withdifferent coefficients of thermal expansion (CTEs) within the leadframepackage 100 cause the leadframe package 100 to become warped. Thewarpage is such that the center of the leadframe package 100 extendsaway from a plane passing through two opposing ends of the leadframe 102due to the leadframe 102 contracting faster and to a greater overallamount than an encapsulant because of a higher CTE. Also, the leadframe102 at these small thicknesses can be very fragile and can benefit fromadditional supporting structure during the assembly and manufacturingprocess. The leadframe package 100 is manufactured according to thebelow description to minimize the effects of different cooling rates andleadframe fragility.

The leadframe 102 has the first side 111 and the second side 113opposite the first side. A protection layer 104 is deposited orotherwise formed on the second side of the leadframe 102. The protectionlayer 104 is a thin layer of plating material that acts as oxidationprotection and may act as a mask for the leadframe 102. The protectionlayer 104 is made of a suitable protective material, such as gold orsilver. In other embodiments, the protection layer 104 includes morethan one layer, such as a stack of three layers made of nickel,palladium, and gold, respectively. The protection layer 104 includesopenings 106 that expose the second side of the leadframe 102.

The first side of the leadframe 102 is etched to create the first groupof recesses 108. These first recesses 108 are aligned with the openings106 on the second side of the leadframe 102 such that the first recesses108 are directly opposite to the openings 106. The first recesses 108 inthe first side of the leadframe 102 create indentations that may extendmore than half way into the leadframe 102. The first recesses 108 have adecreased cross-sectional area between the first side and a bottom ofthe recesses measured in planes parallel to the first side of theleadframe 102. In some embodiments, the cross-sectional area decreasesalong a depth of the recesses. In some embodiments, each one of thefirst recesses 108 has a sidewall with an elliptical curvature whenviewed from the side shown in FIG. 1. In other embodiments, each one ofthe first recesses 108 has a cross-sectional shape of a portion of acircle. And in yet another embodiment, each one of the first recesses108 has a cross-sectional shape of half of a circle, as is shown inFIG. 1. In other words, walls of the recesses 108 and 110 are curved.

The first side of the leadframe 102 is also etched to create the secondgroup of recesses 110. The second recesses 110 are not aligned with theopenings 106 on the second side of the leadframe 102. Instead, thesecond recesses 110 are directly opposite to the protection layer 104.The second recesses 110 in the first side of the leadframe 102 createindentations that may extend more than half way into the leadframe 102.These recesses are curved however other contours are possible.

In some embodiments, the first recesses 108 have a similarcross-sectional shape or dimensions to that of the second recesses 110.The first recesses 108 and the second recesses 110 may be formed at thesame time or by the same process. In some embodiments, the protectionlayer 104 is added to the second side of the leadframe 102 beforeetching of the first side of the leadframe 102 to form the first andsecond recesses 108 and 110 on the first side of the leadframe 102.

FIG. 2 is a cross-sectional view of the electrical contacts 202 formedin the second group 110 of the recesses of the leadframe 102 of FIG. 1.The first group 108 of the recesses is not filled by the electricalcontacts 202. The first group 108 is filled by the encapsulant 204formed on the first side 111 of the leadframe 102. The electricalcontacts 202 are made of a conductive material, such as from metals andmetal alloys, like solder. Each of the electrical contacts 202 may beidentically shaped or sized in some embodiments. In other embodiments,the electrical contacts 202 may include electrical contacts of differentshapes or sizes. In one embodiment, each one of the electrical contacts202 is spherical, and at this point in the manufacturing process thespherical electrical contacts resemble a ball grid array. The electricalcontacts 202 have a thickness that exceeds the depth of the secondrecesses 110 such that after the electrical contacts 202 are depositedin the second recesses 110, the electrical contacts 202 protrude fromthe surface of the first side of the leadframe 102. In one embodiment,more than half the volume of each of the electrical contacts 202protrude from the first side of the leadframe 102. Said differently, aportion of each electrical contact is within the leadframe and a portionof each electrical contact is above the first side 111 of the leadframe.

After depositing the electrical contacts 202 in the second recesses 110,the first side of the leadframe 102 is covered in the first portion ofthe encapsulant 204, the first encapsulant. The first encapsulant 204fills the first recesses 108. In one embodiment, the first encapsulant204 covers the entirety of the electrical contacts 202. In anotherembodiment, the first encapsulant 204 only partially surrounds theelectrical contacts 202, with a portion of each of the electricalcontacts 202 protruding from a surface of the first encapsulant 204. Insome embodiments, the first encapsulant 204 is a resin molding.

The first encapsulant 204 provides additional structural support to theleadframe 102 during the remaining manufacturing steps and during use.The first encapsulant 204 may require preheating the encapsulant priorto application and then cooling as part of a curing process. In someembodiments, the first encapsulant 204 is cured before proceeding to anyremaining manufacturing steps. In other embodiments, the firstencapsulant 204 is not cured before proceeding with later manufacturingsteps. The curing of the first encapsulant 204 at this step wouldnormally cause warpage; however because the leadframe 102 is stillexposed, the leadframe 102 can be secured during curing to preventwarpage.

FIG. 3 is a cross-sectional view of the leadframe 102 of FIG. 2 flippedover with a third group of recesses etched in the second side 113 of theleadframe 102. The third recesses 302 are etched into the second side ofthe leadframe 102. The third recesses 302 are aligned with the openings106 in the protection layer 104 on the second side of the leadframe 102such that the third recesses 302 are directly opposite to the firstrecesses 108, now filled with encapsulant 204. The protection layer mayact as a mask for this etching. The third recesses 302 in the secondside of the leadframe 102 create indentations in the leadframe 102 thatextend to the encapsulant 204. When etched, each of the third recesses302 has encapsulant protruding into the recess towards the second sideof the leadframe 102. The third recesses 302 may have curvature similarto the recesses described above. In some embodiments, the third recesses302 have a similar cross-sectional shape or dimensions to that of thefirst recesses 108, except for a portion removed due to the protrusionof the encapsulant 204.

The third recesses 302 combine with the first recesses 108 to isolateside portions of the leadframe 102 from the center of the leadframe 102.The side portions of the leadframe 102 once separated from the leadframe102 become the leads 304. The leads 304 are coupled to a first subset203 of the electrical contacts 202, with at least one of the electricalcontacts 202 associated with a respective one of the leads 304.

FIG. 4 is a cross-sectional view of a die 402 attached to the leadframe102 of FIG. 3. The semiconductor die 402 is attached to the second sideat a center of the leadframe 102. The semiconductor die is attached tothe leadframe using standard die attach processes. For example, in oneembodiment, a die attach layer 404 secures the semiconductor die 402 tothe second side of the center of the leadframe 102 through theprotection layer 104. In some embodiments, the semiconductor die 402covers all or most of the center of the leadframe 102 or the protectionlayer 104.

In one embodiment the semiconductor die 402 is electrically coupled tothe leads 304 by connectors or wires 406. In some embodiments, firstends of the connectors 406 are coupled to respective pads on a topsurface of the semiconductor die 402 opposite the die attach layer 404.In some embodiments, second ends of the connectors 406 are each coupledto one of the leads 304 on an opposite side as compared to theelectrical contacts 203. In one embodiment, the connectors 406 are bondwires.

FIG. 5 is a top plan view of the leadframe 102 and the semiconductor die402 of FIG. 4, with FIG. 4 taken at cross-section line AA of FIG. 5. Ascan be appreciated from FIG. 5, the semiconductor die 402 may haveconnectors 406 emerging from multiple sides and extending towards theleads 304 on multiple sides of the leadframe package 100. As also can beappreciated from FIG. 5, the openings 204 may extend well beyond thedimensions shown in FIG. 4 depending on the particular layout of theleadframe package 100. Although FIG. 5 depicts leadframe package 100 asbeing asymmetrical in first and second axes, other embodiments aresymmetrical in one or more axes. Also, as is shown in FIG. 5, theleadframe package 100 may include one or more leads which are notcoupled to the semiconductor die 402. These uncoupled leads may or maynot have corresponding electrical contacts 202 on the opposing side ofthe side shown.

FIG. 6 is a cross-sectional view of the semiconductor die 402 andleadframe 102 of FIG. 4 with the second encapsulant 602 on the secondside of the leadframe 102. After the semiconductor die 402 has beensecured to the center of the leadframe 102 and has been electricallycoupled to the leads 304, the second side of the leadframe is coveredwith the second encapsulant 602. The second encapsulant 602 may requirepreheating the encapsulant prior to application and then cooling as partof a curing process. The second encapsulant 602 fills the third recesses302. In one embodiment, the second encapsulant 602 covers the entiretyof the second side of the leadframe 102, the semiconductor die 402, thedie attach layer 404, and the connectors 406. In some embodiments, thesecond encapsulant 602 is a resin molding, and in one embodiment thesecond encapsulant 602 is the same material as the first encapsulant204.

In some embodiments, the second encapsulant 602 combines with the firstencapsulant 204 through the first recesses 108 and third recesses 302.In one embodiment the second encapsulant 602 is combined with the firstencapsulant 204 to form a unitary block of encapsulant. In otherembodiments the first and second encapsulants 204 and 602 remain asdistinct pieces that are secured together.

The first and second encapsulants 204 and 602 come together tocompletely fill openings in the leadframe 102 separating the leads fromthe center of the leadframe 102. In some embodiments, the openings inthe leadframe 102 have a non-uniform gap distance (a non-uniform shapefrom the first side to the second side of the leadframe). A firstsidewall of the opening and a second sidewall of the opening have twocurved portions 207, 209 that meet in a point 211. The second sidewallbeing opposite the first sidewall. In some embodiments, the openingswill have a cross-sectional shape similar to an hour glass as the firstand third recesses 108 and 302 join together from opposing sides. Inthese embodiments, the gap distance is at the smallest at approximatelya middle point of the sidewall, forming a discontinuity in the line ofthe sidewall in which the line of the sidewall is different on eitherside of the middle point.

In some embodiments, the thickness of the second encapsulant 602 isgreater than the thickness of the first encapsulant 204. In oneembodiment, the thickness of the second encapsulant 602 is approximatelyfive times the thickness of the first encapsulant 204 (prior to theback-grinding that exposes the surface 305).

In some embodiments, the second encapsulant 602 is cured beforeproceeding to any remaining manufacturing steps. In other embodiments,the second encapsulant is not cured before proceeding with latermanufacturing steps. The curing of the encapsulant 602 would normallynot cause warpage due to the structural support to the leadframe 102provided by the first encapsulant 204.

At this point in the manufacturing process, the center of the leadframe102 has no structural supports contacting the leadframe 102 other thanthe first and second encapsulants 204 and 602. To achieve thisconfiguration, it is not possible to apply encapsulant to the first andsecond sides of the leadframe 102 simultaneously that completely coversthe center of the leadframe 102. An edge 213 of the lead 304 is exposedthrough the encapsulant 204, 602.

FIG. 7 is a cross-sectional view of the encapsulated leadframe package100 of FIG. 6 after removal of some of the first encapsulant 204 on thefirst side of the leadframe 102 to expose the electrical contacts 202. Aremoval process is applied to the side of the first encapsulant 204 awayfrom the leadframe 102 to remove a portion of the first encapsulant 204.In one embodiment, the removal process includes backgrinding theleadframe package 100. In other embodiments the removal process includesplanarization. Once the removal is complete, a new planar surface 307 ofthe first encapsulant 204 is created that includes openings in the firstencapsulant 204 that expose the surface 305 of the electrical contacts202. The electrical contacts 202 are also partially removed such thatthey have contact surfaces 702 that are planar with the new planarsurface of the first encapsulant 204. In this configuration, theelectrical contacts 202 are an embedded ball grid array that becomesfunctionally similar to a land grid array. Each one of the electricalcontacts 202 in the land grid array may provide electrical or thermalconnections to the semiconductor die 402 from outside of the leadframepackage 100. A second subset of the electrical contacts 202 are coupledto the center of the leadframe 102 and thus to the semiconductor die402. The first subset of the electrical contacts 202 are connected tothe semiconductor die 402 through the leads 304 and connectors 406. Inone embodiment, sides of the leads 304 are also exposed through thefirst and second encapsulants 204 and 602.

FIG. 8 is a cross-sectional view of an alternate embodiment of aleadframe package in which leads do not extend to an edge 801 of anencapsulant 808. The leadframe package 800 shares many similarities tothe leadframe package 100. For instance, the leadframe package 800 alsoincludes a leadframe 802, a protection layer 804, electrical contacts806, encapsulant 808, leads 810, a semiconductor die 812, a die attachlayer 814, connectors 816, and contact surfaces 818. These componentsare similar to those described above with respect to leadframe package100, except as discussed below.

As can be appreciated from FIG. 8, the leads 810 do not extend to theedge of the encapsulant 808. Instead, the ends of the leads 810 wereetched so that only the electrical contacts 806 extend to any one of thesurfaces of the encapsulant 808. The contact surfaces 818 of theelectrical contacts 806 are coplanar to a surface of the encapsulant808. In one embodiment, ends of the leads are etched by the same etchingused to form openings that separate the leads 810 from the leadframe802. In other embodiments the ends of the leads are etched by adifferent process or at a different time. In these embodiments, theencapsulant 808 completely surrounds all elements of the leadframepackage 800 except the electrical contacts 806 at the contact surfaces818.

FIG. 9 is a cross-sectional view of an alternate embodiment of aleadframe package in which two semiconductor die are attached to aleadframe in a stack. The leadframe package 900 shares many similaritiesto the leadframe package 100. For instance, the leadframe package 900also includes a leadframe 902, a protection layer 904, electricalcontacts 906, encapsulant 908, leads 910, a first semiconductor die 912,a die attach layer 914, first connectors 916, and contact surfaces 924.These components are similar to those described above with respect toleadframe package 100 except, as discussed below.

FIG. 9 highlights an embodiment that includes a second semiconductor die918 stacked on the first semiconductor die 912. In one embodiment, thesecond semiconductor die 918 is smaller in length or width than thefirst semiconductor die 912. This allows access to the contacts on thetop of the first semiconductor die 912. As is shown, first connectors916 are similar to the connectors 406 shown in FIG. 4. In addition, thesecond semiconductor die 918 may be electrically coupled to the leads910 using second connectors 920 or to the first semiconductor die 912using third connectors 922. The connections at ends of the first,second, or third connectors 916, 920, and 922 may be shared with anyother connectors, but the connections may also singularly electricallycouple one of the first and second semiconductor dice 912 and 918 toeach other or a lead without electrically coupling to another connector.The second and third connectors 920 and 922 may be made of the samematerial as the first connectors 916, such as bond wires for example.

In some embodiments, the dimensions of the leadframe package 900 aresimilar to that of the leadframe package 100. In one embodiments, theencapsulant 908 may have a greater ratio than the semiconductor package100 of encapsulant thickness above a first side of the leadframe 902adjacent to the protection layer 904 compared to encapsulant thicknessabove a second side of the leadframe 902, the second side opposite thefirst side.

The various embodiments described above can be combined to providefurther embodiments. Aspects of the embodiments can be modified, ifnecessary to employ concepts of the various patents, applications andpublications to provide yet further embodiments.

These and other changes can be made to the embodiments in light of theabove-detailed description. In general, in the following claims, theterms used should not be construed to limit the claims to the specificembodiments disclosed in the specification and the claims, but should beconstrued to include all possible embodiments along with the full scopeof equivalents to which such claims are entitled. Accordingly, theclaims are not limited by the disclosure.

1. A device, comprising: a leadframe package including: a semiconductordie; a leadframe having a first side and a second side opposite thefirst side, the leadframe having a plurality of recesses in the firstside, the semiconductor die coupled to the second side of the leadframe;a plurality of electrical contacts, the plurality of electrical contactsin a first group of the plurality of recesses, the plurality ofelectrical contacts having a first portion extending into a respectiveone of the plurality of recesses and a second portion extending awayfrom the respective one of the plurality of recesses; and an encapsulanton the first side of the leadframe and on the second side of theleadframe, the encapsulant around respective sides of the second portionof the electrical contacts.
 2. The device of claim 1, wherein theplurality of electrical contacts each have a surface that is coplanarwith a surface of a first side of the encapsulant.
 3. The device ofclaim 2, wherein the encapsulant has a second side opposite the firstside, the first and second sides of the encapsulant being in a parallelplane to the first side of the leadframe.
 4. The device of claim 3,wherein a thickness of the encapsulant between the second side of theencapsulant and the second side of the leadframe is no more than fivetimes the thickness of the encapsulant between the first side of theencapsulant and the first side of the leadframe.
 5. The device of claim1, wherein a second group of the plurality of recesses have a decreasingcross sectional area from a surface of the first side of the leadframeinto the leadframe.
 6. The device of claim 5, wherein each one of thesecond group of the plurality of recesses is a hemisphericalindentation.
 7. The device of claim 1, wherein the electrical contactsare solder balls.
 8. The device of claim 1, wherein the leadframe has aplurality of openings, each one of the plurality of openings including arespective one of the plurality of recesses in the second side of theleadframe and a respective ones of a second group of the plurality ofrecesses in the first side of the leadframe, the encapsulant being inthe plurality of openings in the leadframe.
 9. The device of claim 8,wherein the leadframe package further comprises a bondwire coupled at afirst end to the die and coupled at a second end to a lead of theleadframe, the lead separated from the leadframe by one of the pluralityof openings. 10-16. (canceled)
 17. A device, comprising: a leadframehaving a first side and a second side opposite the first side, theleadframe including: a plurality of openings extending from the firstside to the second side, each one of the plurality of openings includinga first curved indentation from the first side and a second curvedindentation from the second side; and a plurality of leads separatedfrom a center section of the leadframe by the plurality of openings. 18.The device of claim 17, wherein at an intersection of the firstindentation and the second indentation form a point.
 19. The device ofclaim 17, further comprising: a plurality of indentations in the firstside of the leadframe; a plurality of contacts in the plurality ofindentations.
 20. The device of claim 19, further comprising: a resinmolding around the leadframe and the plurality of contacts, a firstsurface of the plurality of contacts being exposed through the resinmolding.
 21. A device, comprising: a leadframe having a first side and asecond side opposite the first side, the leadframe including: a centersection having a first recess in the first side; and a first leadseparated from the center section by a second recess in the first sideand a third recess in the second side, the second recess opposite thethird recess in the leadframe; an electrical contact in the firstrecess; a semiconductor die on the second side of the center section ofthe leadframe; and an encapsulant surrounding the semiconductor die andin the second and third recesses.
 22. The device of claim 21 wherein theelectrical contact is a spherical dome.
 23. The device of claim 21wherein the dimensions of the first recess are equal to the dimensionsof the second recess.
 24. The device of claim 21 wherein the dimensionsof the second recess are equal to the dimensions of the third recess.25. The device of claim 21 wherein the second recess is in fluidcommunication with the third recess.
 26. The device of claim 21, furthercomprising: a bond wire having a first end coupled to the semiconductordie and a second end coupled to the first lead.
 27. The device of claim21, further comprising: a second lead of the leadframe separated fromthe center section by a fourth recess in the first side and a fifthrecess in the second side, the fourth recess opposite the fifth recessin the leadframe, the encapsulant in the fourth and fifth recesses. 28.The device of claim 21, wherein the first, second, and third recesseshave a decreasing cross sectional area from a surface of the first sideof the leadframe into the leadframe.